This core will supply large-scale amounts of eukaryotic and prokaryotic expression system-produced proteins. Specifically, mini-proteins will be made in T7-based E. coli expression systems as inclusion bodies. In addition, Lec3.2.8.1-generated ADA, 89.6P and clades C, A and O derivatives of HIV gp140, gp120 and gp140 mini-proteins will be produced. As required, selenomethionine labeling of eukaryotically or E. coli expressed proteins will be undertaken for x-ray crystallography as well as 15N and 13C labeling of E. coli produced proteins for NMR analysis. Large-scale production of various mini-protein constructs will also be conducted. All monoclonal antibody generation, Fab antibody purification and crystallization trials will be established herein.